Folding electronic devices have been used as notebook personal computers, personal digital assistants (PDAs), smartphones, personal computers, and the like. Such a folding electronic device includes two housings that are connected such that they are relatively slidable along their front or back surfaces. For example, Japanese Patent Application Publication (KOKAI) No. 2008-153599 discloses a conventional electronic device having a hinge mechanism that allows two housings to be relatively movable in the thickness direction when they are relatively slid. When the housings are in the open position, their surfaces are flat or at the same level.
The hinge mechanism of the conventional electronic device has a complicated structure, and may cause an increase in size, weight, manufacturing costs, and the like of the electronic device. Further, the hinge mechanism is not suitable for a rotational slide system.